AirHint found the following cheapest return flights from Boston (BOS) to Sao Paulo (GRU) in September 2025 (see full year).

Return flights

22 Sep - 29 Sep	Copa
29 Sep - 06 Oct	Copa
30 Sep - 06 Oct	Copa
29 Sep - 07 Oct	Copa
30 Sep - 07 Oct	Copa
22 Sep - 08 Oct	Copa
21 Sep - 28 Sep	Delta	direct
22 Sep - 08 Oct	Delta	direct
18 Sep - 23 Sep	United
16 Sep - 20 Sep	United
16 Sep - 05 Oct	Delta
19 Sep - 29 Sep	Copa
20 Sep - 29 Sep	Copa

Also check the deals for one-way flights from Boston to Sao Paulo in September.

The deals are updated regularly. The prices may go up as tickets are purchased by other travellers. Only the cheapest flights are offered. Select a price to book and secure these cheap prices.

Book a cheap hotel in Sao Paulo

Cheap car rent in Sao Paulo

Cheapest return flights from Boston to Sao Paulo in September from 413€

Return flights